jennifer davis has the story. >> reporter: in the shadow of the pentagon under bright and sunny skies, the president and defense secretary joined 200 families to remember a day nine years ago when the world as we all knew it was forever changed. >> on a day much like this, the calm of a clear september morning was shattered by the worst act of terrorism in our nation's history. >> reporter: the president layed a wreath in memory of those who died that day. and while he didn't mention the controversy swirling around a florida paster who planned to burn the koran, he did appeal to the nation to honor the memory of those killed on 9/11 by valuing diversity and tolerance. >> as americans we are not and never will be at war with islam. it was not a religion that attacked us that september day, it was al-qaeda. >> reporter: once the official ceremony wraps up, the families search for the bench inscribed with the name of their loved one. >> i don't think you can move past the sadness. but when i come here, i do feel happy because i do realize that people are coming here and remembering. >> r